This research field is located between microwaves and optics, and thus seeks to take benefit of the advantages of each of these scientific fields. The goal is to take benefit of the special properties of some optical devices, such as very high Q resonators or optical fiber delay lines, which may be used for filtering applications or oscillator stabilization at microwave frequencies. To this purpose, the microwave signal is converted to optics using an optical carrier, and then converted again to microwaves using a fast photodiode.
The goal is to realize microwave sources with ultimate phase noise performance in a small volume, and also to be able to distribute these signals in a system using optical fibers. Another goal is to generate with this approach ultra high frequency signals, in the millimetre wave range (30 GHz to 100 GHz, and further). This includes investigations on integration, modelling and characterization of these systems. The modelling approach is based on the implementation of equivalent models of the optical devices in electronic CAD tools. The characterization approach includes the measurement of all the noise sources in the system : optical and electrical.
Optical resonator realized with a quartz disk for microwave filtering (optical Q = 4 109)
Microwave frequency discriminator based on a 4 km optical delay line